Half metallicity in Cr substituted Fe2TiSn

Abstract

Band structure tailoring has been a great avenue to achieve the half-metallic electronic ground state in materials. Applying this approach to the full Heusler alloy Fe2TiSn, Cr is introduced systematically at Ti site that conforms to the chemical formula $${\text{Fe}}_{2} {\text{Ti}}_{{1 - x}} {\text{Cr}}_{x}$$ Fe 2 Ti 1 - x Cr x Sn. Compositions so obtained have been investigated for its electronic, magnetic, and electrical transport properties with an aim to observe the half-metallic ferromagnetic ground state, anticipated theoretically for Fe2CrSn. Our experimental study using synchrotron X-ray diffraction reveals that only compositions with $$x \le$$ x ≤ 0.25 yield phase pure L2$$_1$$ 1 cubic structures. The non-magnetic ground state of Fe2TiSn gets dramatically affected upon inclusion of Cr giving rise to a localized magnetic moment in the background of Ruderman–Kittel–Kasuya–Yosida (RKKY) correlations. The ferromagnetic interactions begin to dominate for x = 0.25 composition. Results of its resistivity and magnetoresistance (MR) measurement point towards a half-metallic ground state. The calculation of exchange coupling parameter, $$\hbox {J}_{{ij}}$$ J ij , and orbital projected density of states that indicate a change in hybridization between 3d and 5p orbital, support the observations made from the study of local crystal structure made using the extended X-ray absorption fine structure spectroscopy. Our findings here highlight an interesting prospect of finding half-metallicity via band structure tailoring for wide application in spintronics devices.

Observation of Griffiths-like phase in the quaternary Heusler compound NiFeTiSn

“…In many instances, spin glass are found to show a broad hump like feature in the heat capacity (C p versus T ). In our data, we rather observe a sharp rise in the Cp/T vs T 2 plot, which is not a standard feature of the glassy magnetic phase [61]. Such low-T upturn below T N can be taken as an evidence for the onset of bulk magnetic ordering in the sample.…”

“…This value is twice as high than the full Heusler Fe 2 TiSn [5]. The absence of λ-like anomaly in the heat-capacity data is not uncommon among Heusler family of compounds [60,61].…”

Observation of Griffiths-like phase in the quaternary Heusler compound NiFeTiSn

“…This value is twice as high than the full Heusler Fe 2 TiSn [5]. The absence of λ-like anomaly in the heat-capacity data is not uncommon among Heusler family of compounds [60,61]. In many instances, spin glass are found to show a broad hump like feature in the heat capacity (C p versus T).…”

Electronic, magnetic, and structural properties of NiFeMnAl

“…Among various materials considered for practical applications in spintronics, Heusler alloys have attracted particular attention in recent years, largely due to their high Curie temperature, often significantly higher than the room temperature [12][13][14][15][16][17][18]. Many Heusler compounds have been theoretically predicted to be half-metallic [19,20], and in some cases the half-metallicity was confirmed experimentally [21][22][23][24]. In addition to half-metallicity, Heusler alloys have been also reported to exhibit other interesting properties, such as shape-memory effects [25,26] and topological states [27,28].…”